In an aircraft design, a continuous flow of hot air is bled from one part of a gas turbine engine, cooled, and provided to a specific user application. A heat exchanger may be used to cool the hot air.
Heat exchangers in aviation precoolers require the use of interrupted fins such as strip or louver fins having a straight fin geometry with no embellishment. Traditional perforated plate-fin heat exchangers used in other applications are typically stamped constructions, most often with sharp/trapezoidal plate geometries. The cooler matrix is interpenetrated by tubes in some instances. A lesser known method involves the use of perforated fins combined with contracting/expanding passages to control thermal boundary layer growth.